The swinging rigs have been known for several years. They were first used in model boats. To our knowledge the first person to use them in crewed boats, was K. R. May in 1975 with his xe2x80x9cBoomspritxe2x80x9d. (Published by AYRS in their No. 81). Later swinging rigs have been offered commercially for crewed boats, the most outstanding being the xe2x80x9cAerorigxe2x80x9d developed by Ian Howlet and Carbospars Ltd, United Kingdom, in 1990 (European patent application no EP 0 392 848 A1).
We think that these rigs, and specially the Aerorig the most successful, have some important drawbacks. The windward efficiency of these rigs is poor, due we believe to the lack of the jib luff tension, to the great thickness of the mast, to the flexibility of the top of a mast without shrouds, and to the lack of roach on the main sail.
Also, the union of the boom-yard to the mast is a bad engineering solution as it forces the great tensions of the main sail and the jib to be absorbed by a rigid punctual junction. This rigid junction also makes assembly and disassembly mote difficult, prevents the variation of the distance between boom and deck, and prevents the tensioning of the sails downwards. Being the rig compensated, and being controlled only the main sail sheet, its rotational stability is bad, being difficult to steady the rig with feeble winds, forcing reefing to be made simultaneously in both sails, and making the addition of more sail area difficult.
An improved rotary gear for sailing boats is provided wherein the connection of the boom to the rest of the rig is such that on the horizontal plane the boom must rotate simultaneously with the rest of the rig, but that it can move up and down in the vertical plane in order to give tension to the sails and wherein the axis widens as it comes through the deck creating a base wide and strong, making it possible to control the rotation of the whole rig from the base, not only because of the necessary rotation control mechanisms, but also because the remaining rig elements are forced to rotate with the base, which permits also the use of rotating shrouds and stays to help in supporting the mast.